Page 1 of 1

Carb Sync

Posted: Tue Oct 30, 2007 4:55 pm
Author: kiwiz
Hi
I decided to by a vacuum gauge set from Z1 enterprises and attaching it to the 4 carbs on my J showed that one carb was a single graduation different from the remaining three. Is this sufficent to warrant a tweak or should I leave well enough alone?

I have had a look at the linkage between the carbs which is painted yellow. I assume this is the adjustment. The lock nut seems quite difficult to access with my 3/8 socket set and getting a small spanner around it equally difficult. Is there some special tool or trick to loosen it ? Does anyone have any comment on which way to turn the adjuster. The vacuum is 1 gradation lower on the #4 carb?

Posted: Tue Oct 30, 2007 7:04 pm
Author: Pigford
If the bikes running OK, don't bother. The gauges aren't always spot on anyhow :wink:
Recheck em in a couple of hundred miles, and see if they've drifted further out of sync. With any luck #4 may drift IN :P

Posted: Thu Nov 01, 2007 3:24 pm
Author: simon gilling
Pigford is right, the gauges may be slightly off. Take a note of the current readings for each carb then swap the gauge with the 'one graduation out' reading to another cylinder and see if the gauge gives the same reading as the previous gauge or is still a graduation out.

If it is running smoothly at idle and picks up nicely, then I would leave well alone, as most carb linkages shift as you tighten the lock nuts.

Regards

Simon

Posted: Tue Nov 06, 2007 11:24 am
Author: Berne Armstrong
These gauges are widely available and good for the money if you know what I mean.

If only 'one graduation out' then I , as others have advised, would leave it.

If in doubt about gauge accuracy, then use one gauge to measure all 4 cylinders, i.e connect the same gauge to all 4 four cylinders in turn.

That way you can eliminate difference in the gauges and not the vaccum readings.

Hope that helps Si. Be nice to see you on another track day..

Berne